An Infrared Defect Sizing Method Based on Enhanced Phase Images

Infrared thermography (IRT) is a full-field, contactless technique that has been widely used for nondestructive evaluation of structural materials due to many advantages. One of the major limitations of IRT is the fuzzy edge and low contrast in the inspected images—as well as the cost of the system. An efficient image post-processing with an affordable and portable device is of great interest to the engineering society. In this study, a convenient and economical inspection system using common halogen lamps was constructed. The corresponding image-processing scheme, which includes Fourier phase analysis and specific image enhancement was developed to identify defects with sharp and clear edges and good contrast. This system was applied to localized of defects in glass-fiber-reinforced composite panels. The results showed that defects with an effective diameter as small as 5 mm can be detected with excellent image quality. As a conclusion, the developed system provides an economic alternative to traditional infrared thermography which is able to identify defects with good qualities.

Phase Analysis for Dyssynchrony by MPI and MUGA

Fourier phase analysis can be used to assess dyssynchrony from nuclear images, such as multi-gated acquisition (MUGA) radionuclide angiography, gated blood-pool SPECT, and gated SPECT myocardial perfusion imaging. This chapter reviews the technical background of Fourier phase analysis with these imaging modalities and demonstrates how it measures ventricular dyssynchrony. The major clinical application of ventricular dyssynchrony assessment is to improve response to cardiac resynchronization (CRT) in patients with heart failure. This chapter introduces the current practice of CRT and the potential factors related to CRT response, and then reviews the clinical studies of the above phase analysis techniques for increasing CRT response.